This invention relates to safety and arming devices for use with fuzes and more particularly, to a magnetic sensor which senses muzzle exit, spin rate and count turns.
A safety and arming device is a required element of a munition to ensure that the munition is not armed and detonated until the desired time. The safety and arming device (S & A) is part of a munition's fuze and prevents arming of the fuze until certain conditions are met.
MIL-STD-1316 requires two unique environments or occurrences for fuze arming. The first environment utilized is usually setback for gunfired munition fuzing. Setback acceleration of gunfired munitions, due to its large magnitude, is an easily mechanically sensed environment. Fuze power is frequently not available at setback necessitating a mechanical environment sensor. Effective mechanically sensed second environments are much more difficult as set forward and spin, for example, can be relatively low, difficult to mechanically sense, and not sufficiently unique to gunfire to provide adequate safety. A second environment, electrically sensed, such timing, barrel escape or turns counting can be used to increase safety and satisfy MIL-STD-1316.
Many different setback determination devices exist, such as U.S. Pat. No. 5,693,906, entitled “Electro-Mechanical Safety And Arming Device”, which is commonly owned with this application. Muzzle exit determination and turns counting is also provided in many prior art devices, such as U.S. Pat. No. 5,497,704, entitled “Multifunctional Magnetic Fuze”, which is also commonly owned with this application. The entire contents of these references are hereby incorporated by reference.
There is always a need to make the safety and arming devices of any device utilizing a fuze as safe as possible.